Automatic valve for fluid-operated tools



Aug. 26, 1930. E. F. TERRY. JR

AUTOMATIC VALVE FOR FLUIID OPERATED TOOLS Filed Feb. 12, 1927 v\ \\w\w WE.

ri fr Kfm/afi@ a-tkatmq l turn stroke,

i i Patented Aug. 26, 1930 EDWARUF. TERRYQ'JR., cnn-envian, cenoRAno; AssieironynYiMEsNE ASSIGNMENTS, To Y'funn GARDNER-:neutraalcompany', or iQUiNeYjfiLLrnois, -A conroRA'rIoN orf DELAWARE e AUTOMATIC vanvnrjon Finaref-orsnaren".iooLs Y Appiicaaon mea Lretruary 12, 19271 serial 'Non 167,764.

A Y The present invention relatesto automatic Valves for pneumatic: andk similar-tools, and

iss in the nature'oi an improvementeonthe .a

' structure shownrin my earlier PatentNum- 5 ber 1,728,312, `grantedSeptember 17,1929. The object is to provide arnovel valve that is exceedingly quick and. effective :in action,

thus making iti peculiarly usefulwith high i speed tools.'

In: the accompanying; drawings Figure l isa longitudinal sectional `View through ay tool equipped with thefpreferred embodiment of the: invention and showing thezworlring `piston `receiving; air for itsre- Figure 2 is a `longitudinal'sectional View showing thepiston` atxthe rearv end ofwits strolreand in a position to receive'air for the forward stroke,

. Figure 3 is a detail )ers vlectivo View ofthe J n Y valve. s s y 1n the embodiment disclosed, acyhnderi is illustrated, containing a piston chamber Y 5, in which a .reciprocatoq7 piston voperates, s Y ,d5 this piston having a hammer extension 'Zion Y,

one side of the cylinder el, and'preferably integral therewith is located a Valve. casing S having. spacedhead chambers 9 and 10 -f n n end face 33 or. the head 24 constitutes a presisuresurfacefopposed to. the pressure surfaces f connected by a reducedbore 11.. i

-U The outer end of the head chamber 9 is providedv with an annular.v channel 12that -c communicates with the rear end ofthe piston chamber 5 through a straight Vshort pas#y sageway or ,port 13.! The inner end ofthe 4head chamber 9 has comi'nunication,withjan1V intermediate portion of the .piston Achamber i vby a straight port 14C.' Between the poorts` 13 and '14, the head chamber 9V has an internal channel 15, from which opeiisan eX- haust outlet 1G to atmosphere.

head. chamber 9 and of less diameter. It is provided at" its iront endwitlr'air annular channel 17 that communicates by Yineans`-of a "short port 18 with the front endfo v'the piston chamber 5 in'advance-"oi' the piston 1 .y

" -,.,vaflve-,-, and its operationis substantiallyy as G. Tlierear endof the head ch'ainberil() 5" iniadvance. o thef-portli. f Between the The head f chamber l() is ksomewhat longer than ther ports 18 and! 191there-is. formed in the head chamber -u kan annular channel 20, with whichzanexhaust port 21 communicates, said exhaustl port beingjbetween the ports 18 and 19; Between the ports 19rk and 2l there is formed inthe head chamber 10 yan annular `channel 22, from which 'leadsI an exhaust outlet 23 opening to atmosphere.

A reciprocatory Valve is located in'the VValue casing 8, and preferably consists of,

This Valve has terminal heads Y two. sections. 24/and 25 that reciprocate' in the, respective Ylhead,chambers 9 and 10. The head 24: therefore has algreater diameter than the head 25,. Projectingrom each head are reduced .shanlrextension's 26 and 27that'operatelin` theborell andv abut against each other.` The heads aref hollow and .are open-ended, and

thefshankf26-27 is providedv with a bore 28 communicating with ther hollowheads. 4 As aY` iconsequence it'will be evident that the head 24 hasaperipheral end pressure surfacev29 and an; inset pressure surface section BO. The endo'f the head, 24 is preferably pro vided, with an inwardly extending; annular v.,laiigefil, theainner surface 32 oflwhich ob-` YioluslyjAequa-lizes the pressure onv an equivalent portion/of the, SuraceBO; The Vinner pressuresurface section 34 andaniiiset pres-V `sureisurface 355 It is provided .with anopposin'gpressure surface 36.1, Said head funk thermore has an annular channel 37 form` ing -a flange-,38,

Extending into the outer en'dsof the head chambers-.Qiandlaref plugs 391'and 40, against Awhich they end facs. 29 and 34 of the valrefhea'ds areresp'ectively adapted to abut. Thefzplug 39 is hollow and forms a supply (portal. leading7 from a throttle, Valve* casing 42,' inrwliich isl asuitable rotatable throttle valve 43;

Thestructure.;constitutes a differential l so f tion. As a consequence it will be evident that the motive fluid entering through the port 41 of the plug 39 will pass behind the piston as the same returns from the end of its cushioned stroke, and drives said piston forwardly. During Athis forward drive the motive fiuid in advance of the piston can exhaust freely through the ports 19 and 21, andby way of the head chamber 10 to the exhaust outlet 23. This is due to the fact that when the front end of the valve is abutted against the plug L10, the flange 38` is in an intermediate position with respect to the channel 22, so that both ports 19 and 21 are open to the exhaust outlet 23. During this stroke, the valve is held in its forward position by pressure against the rear end surfaces 29 and 30, which surfaces minus the surface 32, are sufficient to overcome the pressure against the opposite face of the head 25, material pressure against the surface 34 being cut off' by the contact of said surface against the end of the plug 40. The valve therefore remains in its forward position until the rear end of the piston 6 uncovers the port 14. Vhen this occurs, additional pressure is brought against the surface 33 and the area of this surface plus the area of the surface 35 is sufficient to overcome the pressure against the surfaces 29 and 50,so that the valve is shifted to the position shown in Figure 1. lVhen this occurs, the exhaust ports 19 and 21 are not only cut off by the piston 6, but the exhaust port 19 Ace is cut off from the exhaust outlet 23 by the flange 3 8, while the exhaust port 21 is cut off by reason of the head 25 engaging the end wall of the channel 37. The rearward movement of the valve, however, opens port 14 in rear of the piston to the exhaust outlet 16, as shown. Therefore motive fluid passing through the valve and entering through the port 18 will drive the piston 6 rearwardly, while the exhaust can take place freely through the port 14, head chamber 9 and outlet 16. During this movement the valve will be held in its rearward position by reason of the fluid acting against the surfaces 84 and 35, the combined areas thereof being greater than the area ofthe surface 30 minus the opposing surface 32. As soon as the front end of the piston uncovers the port 19, then motive fluid in the front end of the piston chamber 5 will enter the inner end of the head chamber 10 Vand acting against the surface 36 cooperate with the surface 3() and shift the valve again forwardly or to the position shown in Figure 2.

The above valve is found to have both speed and reliability, and it is so constructed that the five ports 13,y 14, 19, 21, and 18 can be exceedingly short and of relatively large area. Moreover it will be noted that during the working stroke the exhaust in advance of the piston has a peculiarly .said chambers free means of exit, and even after the port 19 is closed by the advance of the piston, the exhaust can still take place through the port 21, so that a full forward stroke of the piston is obtained. It will be noted that the port 18 is not only short, but of large area, thus insuring a' quick return movement of the piston, it being necessary however, that said port 18 be of materially less area than the bore 28, so that there is sufficient pressure in the short end of the head chamber 10 to insure the holding of the va ve in its rear Vposition during the rearward stroke.

From the foregoing, it is thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled in the art, without further description, and it will be understood that various changes in the size, shape, proportion and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

That I claim is:

`1. In a fluid operated tool, a piston cha1nber, a piston therein, and a valve casing having chambers of different diameters, a valve in the casing having portions of different diameters operating in said chambers, and having a set of opposed pressure surfaces of substantially equal area, means for constantly supplying motive fluid to and against said opposing surfaces, ports opening from the valve casing chambers to the piston hamber and controlled by the valve, said valve having a second set of opposing pressure surfaces of unequal area, and trip ports from the piston chamber to the valve casing and controlled by the piston, said trip ports alternately supplying fluid from the piston chamber to 'the valve casing and against the surfaces of the second set for shifting the valve.

2. In a fluid operaterL tool, a piston cham ber, a piston operating therein and a valve casing having head chambers of different diameters, a valve in the casing having heads of different diameters operating in -said head chambers, said heads having one set of opposing pressure surfaces of substantially the same area and a second set of pressure surfaces that differ in area, supply ports opening from the head chambers to the piston chamber on opposite sides of the piston and controlled by the valve heads, means for supplying motive fluid to the head chambers for `passage through the supply ports, said motive fluid having simultaneous access to the opposing pressure surfaces of substantially equal area, and trip ports between thc piston chamber and the head chambers, said trip ports being covered and uncovered by the piston and alternately supplying motive fluid from the piston chamber to the opposing pressure surface of different areas.V

In a fluid operated tool, a piston charnber, a piston operating therein and a valve casing having head chambers of differentv Vof the piston and controlled by the valve heads, means for supplying motive fluid to the outer ends of the head chambers for passage through the supply ports, said motive fluid havingsimultaneous access to the outer opposing pressure surfaces substantially d equal area, and trip ports between the pist0n chamber and the inner ends of the head chambers, said trip ports beine' covered and uncovered by the piston and alternately supplying, motive fluid from the piston '1 chamber to the inner opposing pressure surfaces of different areas.

In a fluid operated tool, a piston chainber'and'a valve casing having yhead chainbers of different diameters, supply ports Aconnecting the outer end portions of the head chambers and the outer end portions of the piston chamber, tripV ports between the inner end portions of the head chambers and the co responding portions of the, piston chamber, a piston in the piston chamber, the ends of said piston respectively covering and uncovering the trip ports, a valve having heads of different diameters in the head chambers, said heads having inner surface' acted on by motive fluidy delivered to the inner ends of the head chambers Vthrough' the trip ports when uncovered by the piston, and said valve heads each having outer surface sections v-.f'hose combined area is greater than the said inner surface thereof, means for supplying motive fluid to theouter ends of the head chambers and against both outer surface sections of one head When the valve is in predetermined position, and means for cutting thev fluidA in the outer end of the head chamber from access toone of the outer surface sections of the head thereof When the valve is in a shifted position.

y5. In a fluid operated tool, a piston chamber and a valve casing havino` headl chan bers of oiflerent diameters, supply ports connecting the fouter end portions of the head chambers and the outer endV portions of the piston chamber, trip ports between the inner end portions of the head chambers and the corresponding portions of the piston chamber, a'piston in the piston chamber, theends of said pistonV respectively covering anduncovering the trip ports, a valve 1 having heads of different .diameters in the head chambers, said heads having inner n surfaces of different areas acted on by motive fluidfdelivered to the inner ends of the head chambers through the trip ports when uncovered by the piston and said valve heads each having outerv surface se tions Whose combined area is greater than the said inner surface thereof, means for supplying motivefiui'd to the outer ends ofthe head chambers and against both outer surface sections of one head when the valve is in predetermined position, and stops against which the heads abut, said stops serving to out off access of the Huid to certain of said outer. surface sections.

6. In a fluid operated tool, a piston chamber, anda valve casing having head chambers of different diameters, supply ports connecting the outer Aend portions of the head chambers and the outer end portions of the piston chamber, trip' ports between the inner end portions of the head chambers and the corresponding portions of the piston chamber, a piston` in the piston chamber, the ends of said piston respectively covering and uncovering the trip ports, a valve having heads of different diameters in the head chambers, said headshaving inner surfaces of different areas acted on by motive fluid delivered to the inner ends of the head chambers through trip ports when uncovered by the piston, and said valve heads having peripheral outer end surface sections of different areas rand second outer surfaces inset from the peripheral surface and of substantially equal effective areas, means for-supplying motiveV fluid constantly to the outer ends` of both head chambers and against the inset surface sections of the heads, and abutments against which the peripheral surfaces alternately abut When the valve is shifted.

7. In a fluid operated tool, a piston chamber and a valve casing having head chambers of different diameters, supply ports connecting the outer end portions of the head chambers and the outer end portions of the piston chamber, trip ports bet-:veen

Vthe inner end portions of the head chambers and the corresponding portions of the piston chamber, a piston in the piston chamber, the ends of said piston respectively covering and uncovering the trip ports, a valve having heads of different diameters in the headl chambers, said heads having inner surfaces acted on alternately by motive fluid delivered to theinner ends of the head chambers through the trip ports when uncovered `by the piston vand said valve heads having outer surface sections Whose combined' area is greater than the said inner surfacesthereof, means for supplying motive fluid to one of the/end chambers and'against the outerend of the valve *head therein, and a passageway lill) los llt)

through the valve for directing motive fluid from said head chamber to the other outer end of the other head chamber and against the outer end of the valve head therein.

8. In a fluid operated tool, a piston chamber and a valve casing having head chambers of different diameters, supply ports connecting the outer end portions of the head chambers and the outer end portions of the piston chamber, trip ports between the inner end portions of the head chambers and the corresponding portions of the piston chamber, a piston in the piston chamber, the ends of said piston respectively covering and uncovering the trip ports, a valve having heads of different diameters in the head chambers, said heads having inner surfaces alternately acted on by motive fluid delivered to the inner ends of the head chambers through the trip ports when uncovered by the piston and said valve head having outer surface sections whose combined area is greater than the said inner surfaces, means for supplying motive fluid to one of the end chambers and against the outer end of the valve head therein, a passageway through thc valve for directing iuid from said head chamber to the other outer end of the other head chainber and against the outer end of the valve head therein, and abutinents against which said valve heads alternately strike and cut olil access of the fluid to portions the outer surfaces of said heads.

9. In a fluid operated tool, a piston chamber and a valve casing having spaced head chambers of different diameters and a reduced bore connecting the head hambers, a piston in the piston chamber, supply ports between the outer portions of the head chambers and the piston chamber on opposite sides of the piston, trip ports between the inner portions of the head chambers and the correspomling` portions of the piston chamber, said trip ports being` covered and uncovered by the piston, means for supplying motive fluid to the outer portion of one of the head chambers, a valve comprising heads in the head chamber provided with reduced shank extensions located in the bore, said heads and shank extensions having a passageway therethrough aflordirnr communication between the outer ends or the head chambers and said heads controlling the supply ports, said heads furthermore having` peripheral end surface sections of different diameters and inset internal end surface sections of substantially tl e saine effective areas operated on by the fluid in the head chambers, and surfaces against which the peripheral .surfaces alternately abut to cut off the access of fluid to said surfaces.

10. In a fluid operated tool, a piston chamber, and a valve casing having spaced head chambers of' different diametes and a reduced bore connecting the head chambers,

a piston in the piston chamber, supply ports between the outer portions of the head chamber and the piston chamber' on opposite sides of the piston, trip ports between the inner portions of the head chambers and the corresponding portions of the piston chamber, said trip ports being covered and uncovered by the piston, a valve comprising heads of different diameters in the head chambers provided with reduced shank e2;- tensions located in the bore and abutted, said heads and .shank extensions having a passageway therethrough affording communication between the outer ends of' the head chambers, and said heads controllingr the supply ports, said heads furthermore having peripheral end surface sections of different areas and inset internal end surface sections of substantially the same effective areas operated on by the fluid in the head chambers, and closures for the outer ends of the head chambers and against which the peripheral ends of the heads abut, one of said closures having a passageway for the supply of' motive fluid to the head chamber thereof and through the valve passageway to the other head chamber, theinner ends of the heads having faces of different areas that are alternately operated on by motive fluid admitted throng-gh the trip ports.

ll. In a fluid operated tool, the combination with a piston chamber and a piston therein, of a valve casing having a chamber, spaced ports opening into the piston chamber and into the valve chamber, an exhaust outlet opening into the valve chamber at a point between the spaced ports, a valve having a head operating in the chamber and provided with a groove that is movable into and out of a position to afford communication between one of the ports and the exhaust outlets, and a liange that is correspondingly movable into and out of a position to afford communication between the other port and the exhaust outlet, said latter port being covered and uncovered by the piston.

l2. In a fluid operated tool, the combination with a piston chamber and a piston therein, of a valve casing having a head chamber, a trip port between the inner end of the head chamber and the piston chamber, said trip port being covered and uncovered by the piston, an exhaust port between the piston chamber and head chamber and spaced from the trip port, an exhaust outlet opening into the head chamber' in a line between the ports, an automatic valve in the valve casing having a head operating in the head chamber, said head having a channel movable to and from a position to afford communication between the exhaust port and the exhaust outlet, and said valve havingV a flange movable to and from a position between the trip port and exhaust outlet "and ymeans fory stopping the valve when moved in vone direction with the channel and' and in a position to be operated against by fluid admitted throughr the trip port when said trip port is uncovered by the piston,

flange in positions to cut ofi the exhaust outlet from theports, and stopping thevalve lwhen moved in theopposite direction in a position to open both ports to the exhaust outlet. s s

13. In a fluid operated tool, the combination with a piston chamber and a piston therein, of a valve casing having yhead chambers, a valve havingfheads that recip-y roeate in said chambers, said-chambers having ports communicating with the piston chamber on opposite sides of the piston and being controlled by the valve, means for supplying motive fluid to one of the head chambers, a passageway through the valve for conducting motive fluid from said head chamber to the other chamber for supplying motive Huid to the piston chamberv through the port thereof, said passageway ture.

having greater capacity than said port, op-

posing pressure rsurfaces on the valve heads that are acted on by the -rnotive fluid in said head chambers, said valve having other opposing pressure surfaces, and means controlled by the piston for alternately delivering fluid under pressure against said other opposing pressure surfaces.

In testimony whereof, l aiiix my vsigna- EDWARD r. TERRY', JR. 

